Threadfin Dragonfish, Echiostoma barbatum Lowe 1843

A freshly collected male Threadfin Dragonfish, Echiostoma barbatum, from off southern Queensland, June 2017. Source: Rob Zugaro / Museums Victoria. License: All rights reserved


A large black dragonfish with a long robust body, a short blunt rounded snout, and jaws of equal length armed with fang-like teeth. The short-based dorsal and anal fins are opposite and far back on the body, the pectoral fins are reduced to a single long ray seperated from three short rays inserted just behind the head, and the pelvic fins are low on the body.

A short bioluminescent barbel or tentacle is present beneath the lower jaw and a large triangular luminous organ is positioned behind the eye. A row of photophores (light organs) runs along the lower surface between the bases of pectoral and pelvic fins. In life, the photophores emit blue and pinkish light.

Cite this page as:
Bray, D.J. 2017, Echiostoma barbatum in Fishes of Australia, accessed 20 Jun 2024,

Threadfin Dragonfish, Echiostoma barbatum Lowe 1843

More Info


Off southern Queensland, around the southern half of Australia to off Dampier, Western Australia. Elsewhere the species is widespread in all oceans at tropical to temperate latitudes - at mesopelagic and bathypelagic depths.


Dorsal fin 11–16; Anal fin 13–19; Caudal fin 18; Pectoral fin 1+3; Pelvic fin 8. Photophores: IP 7–8 + 2, PV 25–28, VAV 15–19; OV 24–27, VAL 14–19, AC 9–13.

Body depth 10–17% SL; head length 14–17% SL; eye diameter 14–21% HL; 1st pectoral-fin ray sometimes reaching to origin of ventral fins.

Snout slightly longer than eye diameter; jaws nearly as long as head, straight, lower jaw slightly shorter than upper; large, barbed, fang-like teeth in jaws, some rigid among smaller teeth; small teeth on vomer, palatines and basibranchials.

Chin barbel generally shorter than head, terminating in bulbs and various filaments, varying with age and between sexes; vertical rows of smaller photophores as well as serial photophores and 2 longitudinal bands of luminous tissue, one along back and one below lateral series; postorbital light organ behind eye above dorsal margin of upper jaw, an elongated triangle, size varying with age and between sexes.

Dorsal and anal fins about equal in size; dorsal adipose fin absent; pectoral fins close behind head, 1st ray unattached to others, elongate; pelvic fins based near ventral profile of body, narrow, short, nearer tail than snout.


To 32 cm SL; 37 cm TL


Blue-black to dark brown in life; fins slightly paler; 1st pectoral-fin ray black; stem of barbel black, terminal bulbs and filaments blue; photophores emitting blue and pinkish light in life.


This voracious predator feeds on smaller fishes such as myctophids and Cyclothone, plus crustaceans such as Gnathophausia species. The species has been found in the stomachs of larger fishes, such as swordfish.


Females mature at a larger size than males, and may grow to a larger size overall. The maximum standard length is 37.0 cm (SL; Gibbs and Barnett 1990).The bioluminescent post-orbital organ is longer in large males than in large females. This suggests that the emitted may be used in courtship.


Of no interest to fisheries, although occasionally taken as by-catch in commercial trawls.


IUCN Red List: Least Concern.


The Threadfin Dragonfish, like many other fishes that live in the oceanic twilight zone, uses its bioluminescence to attract prey and camouflage itself from both predators and prey. The large post-orbital light is sexually dimorphic, and may be involved in species recognition and courtship

Species Citation

Echiostoma barbatum Lowe 1843, Proc. Zool. Soc. Lond. 1843(11): 88. Type locality: off Madeira.


Bray, D.J. 2017


Threadfin Dragonfish, Echiostoma barbatum Lowe 1843


Gibbs RH, Jr. 1984. Melanostomiidae. In: Whitehead PJP, Bauchot M-L, Hureau J-C, Nielsen J, Tortonese E, editors. Fishes of the North-eastern Atlantic and the Mediterranean. Paris: UNESCO. p 341–365.

Gibbs, R.H. Jr. 1986 Melanostomiidae. p. 236-243. In Smith, M.M. & P.C. Heemstra (eds.) Smiths' sea fishes. McMillan, South Africa.

Harold, A.S. 1999. Families Gonostomatidae, Sternoptychidae, Phosichthyidae, Astronesthidae, Stomiidae, Chauliodontidae, Melanostomiidae, Idiacanthidae, Malacosteidae. pp. 1896-1917 in Carpenter, K.E. & Niem, V.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 3 Pp.1397-2068. 

Harold, A. 2015. Echiostoma barbatum. The IUCN Red List of Threatened Species 2015: e.T18256560A21909324. Downloaded on 12 June 2017.

Hopkins, T.L., Sutton, T.T. & Lancraft, T.M. 1996. The trophic structure and predation impact of a low latitude midwater fish assemblage. Progress in Oceanography 38: 205-239.

Kenaley, C.P., Harold, A.S. & Gomon, M.F. 2008. Family Stomiidae. pp. 240-254 in Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Kreuger, W.H. & Gibbs, R.H. 1966. Growth changes and sexual dimorphism in the stomiatoid fish Echiostoma barbatum. Copeia 1966(1): 43-49.

Lowe, R.T. 1843. Notices of fishes newly observed or discovered in Madeira during the years 1840, 1841 and 1842. Proceedings of the Zoological Society of London 11: 81-95.

Parr, A.E. 1927. The Stomiatoid fishes of the suborder Gymnophotodermi (Astronesthidae, Melanostomiatidae, Idiacanthidae) with a complete review of the species. (Scientific results of the third oceanographic expedition of the "Pawnee" 1927). Bulletin of the Bingham Oceanographic Collection Yale University 3(2): 1–123.

Parr, A.E. 1934. Report on experimental use of a triangular trawl for bathypelagic collecting with an account of the fishes obtained and a revision of the family Cetomimidae. Bulletin of the Bingham Oceanographic Collection Yale University 4(6): 1–59.

Regan, C.T. & E. Trewavas. 1930. The fishes of the families Stomiatidae and Malacosteidae. Danish Dana Expedition 1920-22 in the North Atlantic and the Gulf of Panama 6: 1–143, Pls. 1–14.

Robertson, E.M. & Gomon, M.F. 1994. Families Stomiidae, Chauliodontidae, Astronesthidae, Melanostomiidae, Malacosteidae, Idiacanthidae. pp. 251-263 figs 225-235 in Gomon, M.F., Glover, C.J.M. & Kuiter, R.H (eds). The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs

Somiya, H. 1979. 'Yellow lens' eyes and luminous organs of Echiostoma barbatum (Stomiatoidei, Melanostomiatidae). Japanese Journal of Ichthyology 25(4): 269-272.

Sutton, T.T. & Hopkins, T.L. 1996. Trophic ecology of the stomiid (Pisces: Stomiidae) fish assemblage of the eastern Gulf of Mexico: strategies, selectivity and impact of a top mesopelagic predator group. Marine Biology 127(2): 179-192.

Quick Facts

CAAB Code:37109006


Depth:30-4200m (usually 200-2000m)

Habitat:Mesopelagic, bathypelagic

Max Size:37 cm TL

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